摘要:
A reamer for use in root canal preparation includes a blade that is spiral-shaped with a pitch increasing towards the tip, and with a cutting or non-cutting tip. At given points along the length of the spiral of the blade, there is a plurality of gaps, the spiral starting again beyond the gaps, wherein the portion where the spiral is interrupted has either a constant or decreasing cross section linking the two diameters before and after the gap.
摘要:
A method for manufacturing a nonlinear superelastic file comprising the steps of: providing a superelastic file having a shaft and a file axis; providing a fixture including a file groove being defined by one or more displacement members, the file groove configured for receiving the shaft; inserting at least a portion of the shaft into the fixture along the file groove, the portion of the shaft including a first portion of the shaft; contacting the first portion of the shaft with a first displacement member of the one or more displacement members such that the first portion of the shaft is displaced from the file axis thereby forming a first offset portion of the shaft; heating the portion of the shaft while inserted in the fixture to a temperature of at least about 300° C. for a time period of at least about 1 minute to shape-set the portion of the shaft thereby forming a shape-set nonlinear file.
摘要:
An improved process for producing an endodontic instrument with a predetermined taper having a plurality of flutes, each with a predetermined number of spirals over a predetermined length of the instrument are provided. The process basically comprises providing a grinding wheel rotated about a first axis having a plurality of flute grinding ribs and a rolled deformed metal grinding rib extending from a periphery thereof. A rotating wire stock is fed past the plurality of flute grinding ribs and the rolled deformed metal grinding rib at a controlled rate along a second axis so that a separate flute is ground on the wire stock by each of the flute grinding ribs and rolled deformed metal is removed from the ground wire stock by the rolled deformed metal grinding rib. Simultaneously with feeding the rotating wire stock, the grinding wheel or the wire stock is translated such that a distance between the first and second axes increases as the bar stock is fed whereby the wire stock is tapered as the flutes are ground thereon.
摘要:
A root canal is sequentially cleaned in sections from the crown to the apex by dividing it into three sections including an operative coronal portion, an operative middle portion and an apical portion. An operative phase corresponds with each section and specific instrumentation is used in each phase. After an opening is formed into the tooth to provide access into the root canal, the opening is preferably rectified to remove obstructions so that the anatomical root canal can be fully accessed. The pulp material is then sequentially removed from the portion of the root canal above the apical portion of the root canal with a set of instruments and then from the apical portion with another set of instruments. An optional set of instruments can also be used to improve the access into the apical portion such that irrigants can be delivered to the apical portion. Cleaning of the pulp material from the root canal also shapes the root canal to ease filling of the root canal with a filling material. The root canal preparation and shaping are completed while maintaining the original anatomy of the root canal. Each instrument comprises a handle connected to a file. Each file has an abrading portion and terminates at a tip. The files used to clean the portion of the root canal above the apical portion have properties which enable the abrading portion of the file to conform to the configuration of the root canal while simultaneously moving the file in a cleaning motion.
摘要:
The present invention relates to a dental reamer (2) which tapers right down to its tip (1), of the type including helical slits which, on their sides, have cutting lips for boring out dental canals, in which the characteristics of the cutting conditions are defined by, on the one hand, a cutting angle .alpha. determined by the tangent to the cutting edge at the cutting point and the perpendicular to the surface to be cut at this point and, on the other hand, a clearance angle .beta. determined by the plane of the cutting surface and the tangent to the inactive face of the cutting edge, characterized in that the value of the cutting angle .alpha. is greater than or equal to zero and that of the clearance angle .beta. is greater than zero.
摘要:
An endodontic file assembly includes a noncutting file guide along which a flexible file may run. The guide is first inserted into the root canal anchored at its tip and the file subsequently moved along the guide. Disproportionate forces between the file and inner and outer curvatures of the root canal caused by the natural resilience of the file are thereby reduced to provide for more uniform debridement of the inner walls of the root canal.
摘要:
An endodontic instrument is provided for use in performing root canal procedures and comprises an elongate working portion and a chisel tip portion which has removing edges that improve the effectiveness of the instrument in extirpating and enlarging the root canal. The working portion has a non-uniform taper which accelerates from a proximal end of the instrument to a distal end forming a region of enhanced compliance adjacent the tip.
摘要:
An endodontic instrument has a comfortable grip especially for use for a long time of period. A handle of the endodontic instrument includes a cylindrical stem, opposite end portions, and plural brims radially extending from the circumferential surface of the stem in a plate shape juxtaposed in the axial direction of the stem with a predetermined space. When an operator grips the handle of the endodontic instrument, the operator's fingers can readily control the handle through contacts to the brims while the brims engage the bulges of the fingers adequately. The brim preferably has recesses to provide the identification of the instrument's orientation in the finger and also can preferably be made of a resilient material to make the contacts softer to provide better blood flow in finger tips and providing less finger tip stress.
摘要:
A method of fabricating an endodontic instrument by a machining operation is disclosed, and wherein a wire-like rod composed of a titanium alloy is advanced past a rotating grinding wheel at a relatively slow feed rate, with a sufficient depth of cut to remove all of the material on a given surface without over grinding a previously ground surface, and with the grinding wheel rotating at a relatively slow surface speed. The disclosed method is able to efficiently produce endodontic instruments having a high degree of flexibility, high resistance to torsional breakage, and with sharp cutting edges along the working length.